class Test1():
    def _init_(self):
        self.t1='我是父类'
    
    def f(self):
        return '爸爸'

class Test2():
    def _init_(self):
        self.t2='我是子类'

    def f(self,object):
        print(object.f)

a=Test1()
b=Test2()
b.f(a)


def main(object):
    print(object.f())

    return '123'

print(main(a))